How Much Excess Radio Background the EDGES Depth Would Require, With and Without Bounce Cooling

One proposed explanation for a very deep absorption feature is an additional radio background, brighter than the cosmic microwave background alone, against which the gas absorbs. Using the stated cosmology and the brightness-temperature relations described in the Methods, the calculation gives the following headline values: standard depth mK = -267; edges depth mK = -500; amplification needed = 1.87; extra background K at z = 43. The comparison values taken from the published record — including the EDGES and SARAS reports, HERA limits and the Planck optical depth where relevant — are used exactly as published, and the bounce contribution enters only through the named timing, heating or shear inputs. The result is a computed prediction for the delayed-onset history, with its sensitivity to each input stated in the Discussion. This study is simulated and computed from stated assumptions; it is not a measurement.